A particular field of application for the invention is antennas intended to be fitted to apparatuses, missiles, or vehicles, in particularly space-going aircraft, and to be fitted to portions thereof which are subjected to high levels of heating in operation.
For a space-going aircraft, antennas are placed in zones which are exposed to heating due to friction on layers of the atmosphere, in particular around the nose of the apparatus. In such zones, the external structures are constituted, for example, by juxtaposed panels of refractory material, and a known way of protecting antennas against heating is to mask them behind a heat shield. The material from which the heat shield is made must then have low permittivity and very low attenuation losses and must retain these dielectric properties even at very high temperatures. Various materials have been proposed for this purpose, e.g. in the following patent documents: FR 2 483 689, FR 2 553 403, and U.S. Pat. No. 4,358,772.
The object of the invention is to provide a microwave antenna capable of operating at very high temperature without it being necessary to mask it completely by means of a heat shield.